I have a reference tag that is reading an AI value. I use "Format String" property under Numeric category in tag editor to format my values to have one decimal place only. I set this property to ####.# and it converts my tag value to one decimal place correctly, but when I bind a label to this tag or when use this tag as a history tag for trending, the shown value on the Label component and Power chart don't have one decimal place format.
This topic is similar and covers some ways of being able to use the format defined on the tag:
For the power chart, the manual mentions something about axes.dataformat and xTrace.infoBox.dataFormat property, but then doesn't show either of those properties anywhere else.
For what its worth there are quite a few gripes about the current usability of the power chart.